Inflammatory markers and bone mass in children with overweight/obesity: the role of muscular fitness

Longitudinal Associations Between Physical Activity and Sedentary Time and Cardiorespiratory and Muscular Fitness in Preschoolers

Background/Objectives: The impact of physical activity (PA) and sedentary time (ST) during preschool years on the physical fitness (PF) levels of school-aged children remains unaddressed. This study aimed to investigate the associations of objectively measured vigorous physical activity (VPA), moderate-to-vigorous physical activity (MVPA), total physical activity (TPA), and ST in the last year of preschool (age of 6-7 years; n = 77; 51% boys) with cardiorespiratory fitness (CRF) and muscular fitness (MF) in the first grade of school among Estonian children. Methods: We assessed PA (accelerometers), CRF (20 m shuttle run), and MF (z-score of relative upper- and lower-limb muscular strength). Results: In the unadjusted analysis, higher VPA, MVPA, and TPA in preschool were associated with a higher MF in school among boys, while a higher VPA in preschool was related to a higher CRF in school among girls. However, VPA, MVPA, TPA, and ST in preschool were unrelated to CRF and MF among boys and girls after adjustment for baseline age, accelerometer wear time, the corresponding PF item, and parent's education. In addition, a higher PF level in preschool was frequently related to a higher corresponding PF item in school among both genders. Conclusions: Moderate-to-vigorous and vigorous type of activities during final year of preschool, as well the amount of TPA that preschoolers are involved in, are not sufficient to affect their CRF and MF longitudinally. In addition, ST in preschool did not impact the CRF and MF of boys and girls in the first grade.

High muscular fitness level may positively affect bone strength and body composition in children with overweight and obesity

Muscular fitness plays a major role in bone health and body composition in overweight and obese children. It is key that the development of this muscle fitness is affected by absolute isometric strength and dynamic strength.

PURPOSE

To compare bone health and body composition between overweight/obese children considering muscular fitness (MF) levels, and to investigate whether weight-bearing dynamic or absolute isometric strength, both involved in the development of this muscular fitness, are more related with bone health.

METHODS

MF of 59 overweight or obese children (10.1 ± 0.9 years, 27 females) was measured by a countermovement jump (CMJ), handgrip, and maximal isometric strength of knee extension. Participants were divided into four groups depending on their MF level performing a cluster analysis: 16 children with high MF (HMF) in all tests, 18 with high performance in isometric strength (HIS), 15 with high performance in CMJ (HCMJ) and 10 low isometric and low dynamic force values (LMF). Body composition values were measured by dual energy X-ray absorptiometry, and bone strength values were assessed by peripheral quantitative computed tomography. Motor skills were evaluated using TGMD-3. Multivariate analysis of covariance test was applied to analyse bone strength differences between children in the different MF groups, using maturity offset, height and weight as covariates, and correlations were investigated.

RESULTS

HMF excelled in bone health. HIS had higher cortical bone area, periosteal circumference, bone mass, polar strength strain index and fracture load than LMF, while HCMJ only showed better results in trabecular bone area than LMF. HMF had significantly better values of fracture load and periosteal and endosteal circumferences than HCMJ, but not than HIS.

CONCLUSIONS

High MF level shows positive effects on bone health in overweight/obese children. Those with highest isometric strength had better bone health compared to those with higher dynamic strength.

TRIAL REGISTRATION

The research project was registered in a public database Clinicaltrials.gov in June 2020 with the identification number NCT04418713.

Effects of exercise on whole-blood transcriptome profile in children with overweight/obesity

BACKGROUND

The current knowledge about the molecular mechanisms underlying the health benefits of exercise is still limited, especially in childhood. We set out to investigate the effects of a 20-week exercise intervention on whole-blood transcriptome profile (RNA-seq) in children with overweight/obesity.

METHODS

Twenty-four children (10.21 ± 1.33 years, 46% girls) with overweight/obesity, were randomized to either a 20-week exercise program (intervention group; n = 10), or to a no-exercise control group (n = 14). Whole-blood transcriptome profile was analyzed using RNA-seq by STRT technique with GlobinLock technology.

RESULTS

Following the 20-week exercise intervention program, 161 genes were differentially expressed between the exercise and the control groups among boys, and 121 genes among girls (p-value <0.05), while after multiple correction, no significant difference between exercise and control groups persisted in gene expression profiles (FDR >0.05). Genes enriched in GO processes and molecular pathways showed different immune response in boys (antigen processing and presentation, infections, and T cell receptor complex) and in girls (Fc epsilon RI signaling pathway) (FDR <0.05).

CONCLUSION

These results suggest that 20-week exercise intervention program alters the molecular pathways involved in immune processes in children with overweight/obesity.

A 20-week exercise program improved total body and legs bone mineral density in children with overweight or obesity: The ActiveBrains randomized controlled trial

OBJECTIVES

The aim of this study was to investigate the effect of a 20-week exercise program on bone mineral parameters in children with overweight or obesity.

DESIGN

Randomized controlled trial.

METHODS

This study took part from November 21, 2014, to June 30, 2016, in Granada, Spain. A secondary analysis of this parallel-group randomized controlled trial was performed with 77 children with overweight or obesity (9.9 ± 1.2, 65 % boys) who were randomly allocated to exercise or control group. All participants received lifestyle recommendations. The control group continued their usual routines, whereas the exercise group attended a minimum of 3 supervised 90-minute sessions/week of aerobic plus resistance training for 20 weeks. A whole-body scan by dual-energy X-ray absorptiometry was carried out to obtain body composition at total body less head, arms, lumbar spine, pelvis, and legs.

RESULTS

Participants in the exercise group acquired significantly higher total body aBMD (mean z-score [95 % confidence intervals, CI], 0.607 [0.522-0.692]) compared with the participants in the control group (mean z-score, 0.472 [0.388-0.556]); difference between groups, 0.135 standard deviations [95 % CI 0.015-0.255], and legs aBMD (mean z-score, 0.629 [0.550-0.708]); control group (mean z-score, 0.518 [0.440-0.596]); difference between groups, 0.111 [0.001-0.222]; all p < 0.05. There were no significant differences between exercise group and control group at the remaining evaluated regions (p > 0.05).

CONCLUSIONS

A 20-week non-specifically bone-targeted exercise program induced a small, yet significant, improvement on total body and legs aBMD in children with overweight or obesity. Future studies should investigate the interaction of weight status in the bone response to exercise programs.

TRIAL REGISTRATION

Prospectively registered in ClinicalTrials.gov Identifier: NCT02295072.

Are serum thyroid hormone, parathormone, calcium, and vitamin D levels associated with lumbar spine degeneration? A cross-sectional observational clinical study

PURPOSE

Low back pain (LBP) impairs the quality of life and rises healthcare costs. The association of spine degeneration and LBP with metabolic disorders have been reported, previously. However, metabolic processes related with spine degeneration remained unclear. We aimed to analyze whether serum thyroid hormones, parathormone, calcium, and vitamin D levels were associated with lumbar intervertebral disc degeneration (IVDD), Modic changes, and fatty infiltration in the paraspinal muscles.

METHODS

We cross-sectionally analyzed a retrospective database. Patients who visited internal medicine outpatient clinics with suspect of endocrine disorders and chronic LBP were searched. Patients with biochemistry results within 1 week before lumbar spine magnetic resonance imaging (MRI) were included. Age- and gender-matched cohorts were made-up and analyzed.

RESULTS

Patients with higher serum free thyroxine levels were more likely to have severe IVDD. They were also more likely to have fattier multifidus and erector spinae at upper lumbar levels, less fatty psoas and less Modic changes at lower lumbar levels. Higher PTH levels were observed in patients with severe IVDD at L4-L5 level. Patients with lower serum vitamin D and calcium levels had more Modic changes and fattier paraspinal muscles at upper lumbar levels.

CONCLUSION

Serum hormone, vitamin D, and calcium levels were associated with not only IVDD and Modic changes but also with fatty infiltration in the paraspinal muscles, mainly at upper lumbar levels in patients with symptomatic backache presenting to a tertiary care center. Complex inflammatory, metabolic, and mechanical factors present in the backstage of spine degeneration.

Inflammation, Executive Function, and Adiposity in Children With or at Risk for Obesity: A Pilot Study

OBJECTIVE

Obesity is associated with executive function (EF) deficits across the lifespan. Higher body mass index (BMI), obesity severity, and poorer adherence and weight outcomes in obesity treatment have all been associated with EF deficits. Adult literature has begun to emphasize neuroinflammation in obesity as a possible pathway to later cognitive impairment in EF. However, pediatric obesity literature has yet to establish associations between peripheral inflammation and EF. Thus, the present study examined associations and variability in inflammation, EF, and adiposity in children with or at risk for obesity. Additionally, inflammation was examined as a mediator of the relationship between adiposity and EF.

METHODS

Children (N = 39) aged 8-12 years with BMI ≥ 50th percentile were recruited. The NIH Toolbox Cognitive Battery was used to assess performance-based EF. Peripheral inflammation was assessed in fasted sera. Dual-energy X-ray absorptiometry scans were conducted to assess body composition. Linear regression and Hayes' PROCESS Model 4 (Hayes, 2017) were used to evaluate associations between adiposity and inflammation, inflammation and EF, and whether adiposity effects EF through its effect on inflammation.

RESULTS

Positive associations were identified between adiposity and inflammation, and negative to null associations were identified between inflammation and EF. Medium indirect effects of adiposity on EF through inflammation were detected.

CONCLUSION

Pilot evidence suggests greater adiposity is linked with greater inflammation, which in turn is associated with less EF in some domains. Directionality and causality cannot yet be established, but with replication, findings may inform efforts to target EF in pediatric obesity.

The relationship between obesity and bone mineral density in children and adolescents: analysis of the National Health and Nutrition Examination Survey

Childhood and puberty are important period for the skeleton grows. Fat mass, especially visceral adipose tissue, was negatively correlated with areal bone mineral density in children and adolescents. The present study suggests that fat mass, especially visceral adipose tissue, has a slightly negative association with bone development in children and adolescents.

PURPOSE

This study observed the relationship between fat mass and distribution, and areal bone mineral density (aBMD) in children and adolescents.

METHODS

A retrospective study was conducted on US children and adolescents aged 8-19 years. Whole body (less head) aBMD was evaluated. Height (Ht) adjusted Z-scores for aBMD were calculated.

RESULTS

After controlling for age, gender, race, and lean body mass index (LBMI) Z-score, there were significant negative associations between fat mass index (FMI) Z-score and aBMD Ht-Z-adjusted Z-score (β =  - 0.272, P < 0.001, R2 = 0.033). In the linear regression models with aBMD Ht-Z-adjusted Z-score as the dependent variable, the regression coefficients of android fat mass were - 0.241 (P < 0.05, R2 = 0.002), - 0.473 (P < 0.001, R2 = 0.036), and - 0.474 (P < 0.001, R2 = 0.038) for healthy weight, overweight, and obesity group, respectively. The regression coefficients of visceral adipose tissue (VAT) mass were - 0.218 (P > 0.05, R2 = 0.001), - 2.025 (P < 0.001, R2 = 0.044), and - 1.826 (P < 0.001, R2 = 0.039), and the regression coefficients of subcutaneous adipose tissue (SAT) mass were - 0.467 (P < 0.001, R2 = 0.004), - 0.339 (P < 0.01, R2 = 0.024), and - 0.347 (P < 0.001, R2 = 0.018) for healthy weight, overweight, and obesity group, respectively.

CONCLUSIONS

The present study suggests that fat mass has a slightly negative association with bone development in children and adolescents. Trunk fat accumulation, especially visceral adipose tissue, was correlated with the lower level of aBMD. This association was obvious in overweight and obese children.

Cardiorespiratory Fitness and Bone Turnover Markers in Adults With Metabolic Syndrome: The Mediator Role of Inflammation

The relationship between inflammatory markers and bone turnover in adults is well known, and a negative association between cardiorespiratory fitness (CRF) and inflammatory markers has also been described. Hence, we tested whether the association between CRF and bone turnover markers is mediated by inflammatory markers in adults with metabolic syndrome. A total of 81 adults (58.5 ± 5.0 years, 62.7% women) were included in the analysis. CRF was measured by the 6-min walking test. Serum interleukin (IL)-1β, IL-6, IL-10, tumor necrosis factor alpha, high-sensitivity c-reactive protein (hsCRP) and vascular endothelial growth factor, collagen type I cross-linked C-telopeptide, procollagen type I N-terminal propeptide (P1NP), and total osteocalcin were assessed using a sensitive ELISA kit. Body composition was assessed by dual-energy X-ray absorptiometry. Partial correlation was used to test the relationship between CRF, inflammatory markers, and bone turnover markers, controlling for sex, lean mass, and fat mass. Boot-strapped mediation procedures were performed, and indirect effects with confidence intervals not including zero were interpreted as statistically significant. CRF was positively correlated with P1NP levels (r = .228, p = .044) and osteocalcin levels (r = .296, p = .009). Furthermore, CRF was positively correlated with IL-1β levels (r = .340, p = .002) and negatively correlated with hsCRP levels (r = -.335, p = .003), whereas IL-1β levels were positively correlated with P1NP levels (r = .245, p = .030), and hsCRP levels were negatively correlated with P1NP levels (r = -.319, p = .004). Finally, the association between CRF and P1NP levels was totally mediated by hsCRP (percentage of mediation = 39.9). Therefore, CRF benefits on bone formation could be dependent on hsCRP concentrations in this population.

Distinct whole-blood transcriptome profile of children with metabolic healthy overweight/obesity compared to metabolic unhealthy overweight/obesity

BACKGROUND

Youth populations with overweight/obesity (OW/OB) exhibit heterogeneity in cardiometabolic health phenotypes. The underlying mechanisms for those differences are still unclear. This study aimed to analyze the whole-blood transcriptome profile (RNA-seq) of children with metabolic healthy overweight/obesity (MHO) and metabolic unhealthy overweight/obesity (MUO) phenotypes.

METHODS

Twenty-seven children with OW/OB (10.1 ± 1.3 years, 59% boys) from the ActiveBrains project were included. MHO was defined as having none of the following criteria for metabolic syndrome: elevated fasting glucose, high serum triglycerides, low high-density lipoprotein-cholesterol, and high systolic or diastolic blood pressure, while MUO was defined as presenting one or more of these criteria. Inflammatory markers were additionally determined. Total blood RNA was analyzed by 5'-end RNA-sequencing.

RESULTS

Whole-blood transcriptome analysis revealed a distinct pattern of gene expression in children with MHO compared to MUO children. Thirty-two genes differentially expressed were linked to metabolism, mitochondrial, and immune functions.

CONCLUSIONS

The identified gene expression patterns related to metabolism, mitochondrial, and immune functions contribute to a better understanding of why a subset of the population remains metabolically healthy despite having overweight/obesity.

IMPACT

A distinct pattern of whole-blood transcriptome profile (RNA-seq) was identified in children with metabolic healthy overweight/obesity (MHO) compared to metabolic unhealthy overweight/obesity (MUO) phenotype. The most relevant genes in understanding the molecular basis underlying the MHO/MUO phenotypes in children could be: RREB1, FAM83E, SLC44A1, NRG1, TMC5, CYP3A5, TRIM11, and ADAMTSL2. The identified whole-blood transcriptome profile related to metabolism, mitochondrial, and immune functions contribute to a better understanding of why a subset of the population remains metabolically healthy despite having overweight/obesity.

The "Fat but Fit" Paradigm and Bone Health in Young Adults: A Cluster Analysis

The fat but fit paradox has suggested that obese individuals with good fitness levels have lower cardiometabolic risk compared to individuals with normal weight but lower fitness levels. This paradigm has not been explored in the context of bone health. The aim of this study was to test whether categories of fat but fit paradigm assessed by body fat percentage and handgrip strength holds up in young adults and to analyze the relationship between fat but fit categories and bone outcomes. Cluster cross-sectional analyses of data from 499 young adults aged 18 to 30 from Toledo and Cuenca, Spain were conducted. Body fat percentage, handgrip strength, bone mineral content (BMC), bone mineral density (BMD), and dietary nutrients such as, proteins, magnesium, calcium, phosphorus, potassium, and vitamin D were assessed. Cluster analysis of body fat percentage and handgrip z scores resulted in a classification of four clusters that could be interpreted according to Fat Unfit (FU), Unfat Unfit (UU), Fat Fit (FF) and Unfat Fit (UF) categories. ANCOVA models showed that young adults in clusters with higher handgrip strength levels (FF, UF) and with higher key bone nutrients levels (UF) had significantly higher total BMC values than their peers in the UU and FU cluster categories, after controlling for sex, age and height. This study provides two novel conclusions in relation to the fat but fit paradigm: first, it confirms the construct of the four clusters of body fat percentage and handgrip strength, and second, it reinforces the predictive validity of the fat but fit paradigm categories, indicating the positive effect, although it may not just be a causal relationship, of muscular strength and key bone nutrients on counteracting the negative effect of obesity on bone health.